Hawk Mountain Sanctuary hired some new workers last month and, like a lot of summer help, they are getting low wages — $1 per day.

In an attempt to rid Hawk Mountain of a noxious weed called Japanese stiltgrass, the sanctuary has been leasing goats from Pennsylvania farmers.

The goats, chosen for their voracious appetites and iron-like stomachs, are part of a larger, five-year invasive plant management study at Hawk Mountain. It's supported by the state Department of Conservation and Natural Resources, the state Game Commission and the Schuylkill Conservation District.

While the idea may seem novel, goats have been leased to clear vegetation and control invasive plants in many parts of the United States. In 2013, San Francisco International Airport hired goat farmers to clear airport land without harming endangered snakes and frogs. In Detroit, goats have been used to maintain abandoned lots in the bankrupt city.

Locally, Easton has used goats to nosh on Japanese knotweed at Hugh Moore Park.

At Hawk Mountain — which is in Albany Township, Berks County, and East Brunswick Township, Schuylkill County — the goats' mission is to eat as much stiltgrass as they can.

As part of the project, the sanctuary hired an Invasive Plant Research Team, made up of college students.

"It's a little bit off the beaten path for a summer job," said Sam Summer, a team member and Penn State University student.

The team uses a portable electric fence to keep the goats corralled in 1,600-square-foot areas, in the hope that they will gnaw away the stiltgrass.

"At first, we felt pretty ridiculous herding goats down into the woods," said Lucas Wessner, the team manager and a Bloomsburg University student. "They weren't that friendly to us the first day."

The goats wasted no time in proving their worth. In less than a week, the four goats mowed down three 1,600-square-foot pieces of land. Their work was clearly visible. While the vegetation outside the portable fence was knee-high, the inside of the goat pen was all but cleared.

"This was all green with stiltgrass vegetation," said Grif Griffith, a team member and senior at Marshall University in Huntington, W.Va. "You can walk in and tell it's working."

The four plant-munching goats at Hawk Mountain belong to Sandra Miller, who owns Painted Hand Farm in Newburg, Cumberland County.

Miller said she rents her goats on a regular basis, sometimes for an afternoon, other times for a couple of months. They are a mixed breed of Boer, Nubian and Saanen. She's renting the four to the sanctuary for $1 each a day.

Besides using goats, the team at Hawk Mountain has also used propane torches, chemical herbicides, weed trimmers and their bare hands to remove the stiltgrass.

Japanese stiltgrass was brought into the United States in the early 1900s. While it was first documented in Tennessee, the plant has since spread across much of the eastern United States as far west as Texas, according to a fact sheet handed out by Hawk Mountain.

The grass spreads quickly. Each plant can produce 100 to 1,000 seeds annually, allowing the grass to quickly overtake native species. At Hawk Mountain, the grass has taken root in large tracts of the sanctuary, threatening the health of the forest.

Todd Bauman, director of Hawk Mountain's land and facilities, said the money for the invasive plant eradication programs came from the U.S. Department of Agriculture's Natural Resources Conservation Service.

Bauman said the study, in its first year at the sanctuary, will determine how effective goats are in preventing stiltgrass from regrowing. Team members will check to see if the goats eat enough of the plant to prevent it from regrowing and producing seeds.

He said complete removal of the invasive plant species may be impossible, but he hopes to limit its impact.